What are the signs of traffic lights?

There are three kinds of traffic light signs: red light means no passage, green light means no passage, and yellow light means warning. At first, there were only two colors, red and green. Later, after improvement, a yellow light was added. The following is a detailed introduction of traffic lights. Red light: mainly includes three types: one is the command light signal. When the red light is on, vehicles and pedestrians are not allowed to pass; Vehicles must stop outside the stop line, and pedestrians must wait for release at one side of the crosswalk. The second is the lane street lamp signal. Generally, it is installed above the lane that needs independent command, and only plays a command role for vehicles driving in this lane. Vehicles and pedestrians in other lanes still pass by the prescribed signals. The third is the crosswalk light signal. When the red light is on, pedestrians are not allowed to enter the crosswalk. Green light: mainly includes three types: one is the command light signal. When the green light is on, vehicles and pedestrians are allowed to pass. No matter whether it is a motor vehicle or a non-motor vehicle, anyone can go straight, turn left or right when facing the green light signal. Vehicles entering the intersection during the green light should give priority to vehicles already at the intersection and pedestrians in the crosswalk. The second is the lane light signal. When the green arrow light is on, vehicles can pass in the direction indicated by the arrow. The green arrow light refers to the traffic signal light with left, straight and right directional arrows in the green light. The third is the crosswalk light signal. When the green light is on, pedestrians are allowed to cross the crosswalk; When the green light flashes, pedestrians are not allowed to enter the crosswalk, and those who have already entered the crosswalk can continue to pass. Yellow light: there are two main types: first, when the yellow light is on, vehicles and pedestrians are not allowed to pass, but vehicles that have crossed the stop line and pedestrians who have entered the crosswalk can continue to pass; Second, when the yellow light flashes, vehicles and pedestrians must pass under the principle of ensuring safety.